Dressing it down to "Step it Down!"

Hey Everyone :roll_eyes:

I have a problem :(. I need a 24V source and all I have is a 48V DC source. I was wondering what the best way would be to step it down to 24V.

Thank you in advanced everyone! :sweat_smile:

Something like this:

http://www.ebay.com/itm/DC-to-DC-AC-to-AC-Converter-Board-Step-Down-Voltage-Regulator-Module-12-48V-New-/390770262683?pt=LH_DefaultDomain_0&hash=item5afbb9029b

It might depend on how much current you plan to push through.

How do you know how much current you need? Where would I check, I want to run a solenoid valve.

Look at the ratings and requirements for the components you plan to use.

JohnHoward:
Something like this:

http://www.ebay.com/itm/DC-to-DC-AC-to-AC-Converter-Board-Step-Down-Voltage-Regulator-Module-12-48V-New-/390770262683?pt=LH_DefaultDomain_0&hash=item5afbb9029b

Do you know a good place to buy that in Canada that ships quickly?

I tried to find the running current but could not find a value. all I know is that the solenoid valves runs at 24V.

What is the resistance of the solenoid, use a DVM?
Let's say it is 200 ohms.
Then put a 200 ohm resistor in series with it.
48V/400ohms=120ma

wattage for the resistor = 120maX24V=2.88Watts, use a 5 watt or more.

Many (most?) solenoid valves are AC, so if you stick a 24 VAC solenoid on 24 VDC, it will overheat quickly and likely burn out. In order to use an AC solenoid on DC, you have to use a LOWER DC voltage, perhaps 10 or 12 VDC. Check to see what kind of current your valve uses.

So I was able to find the specs of my solenoid valve.

Here they are 8):

V = 24VDC running @ 60Hz, Apparent power = 5.0 VA, Holdong Apparent Power = 2.4 VA

Is it safe to assume that the current range is 95.8mA to 208 mA?

I was also wondering what happens when you put a source that provides a higher current :~
And what is Holding Power? :~

Thanks so much guys~~~~ :stuck_out_tongue:

sexybeast:
So I was able to find the specs of my solenoid valve.
V = 24VDC running @ 60Hz,

DC doesn't run at 60Hz. It runs @ 0Hz.
AC does run @ 60Hz (in N America) and @ 50Hz (in Europe).
Check your specs again.

OK, so 5VA at 24Vac is about 200mA.

But you are using DC. The AC current is limited by both the inductance (the reactance) and the resistance.

So I'd measure the DC resistance, then use that and the current of 200mA to calculate the DC voltage.

The solenoid will only draw as much current as Ohm's Law allows. You could connect it to a 24Vac power supply capable of 200A, it would still only draw 200mA.